1. Field of the Invention
This invention relates generally to reagent strips and reagent strip handling systems, and more particularly, to systems that utilize reagent strips, for example, for the purposes of analyzing body fluids, such as blood, for specific analytes or chemical properties, such as, for example, blood sugar.
2. Description of the Prior Art
Various systems for analyzing the chemical properties of fluids, such as bodily fluids, for specific chemical properties utilizing reagent strips are known. Such systems are often used to measure the glucose level of blood. In such systems, a blood sample is placed on a reagent strip and optically analyzed by a light detection device, such as a light detection photometer, to determine the level of glucose in the blood. Such systems analyze the characteristics of the light reflected from the specimen on the reagent strip to determine specific chemical properties of the analyte specimen. However, the characteristics of the reflected light are determined not only by the chemical properties of the analyte, but also by the chemical properties of the reagent on the reagent strip. Consequently, much effort is expended in attempting to obtain uniformity between different batches of reagent strips that are manufactured; however, due to manufacturing tolerances, there is still some variation. This variation can affect the accuracy of the analytical readings obtained from the specimen.
In order to overcome the variations in readings caused by variations in the reagent strips, several methods for compensating for the variations in the reagent strips have been utilized. In such systems, the characteristics of the reagent strip are first determined, and data defining the particulars of the reagent strip is utilized to compensate the analysis process for variations between batches of reagent strips. The batch specific information that defines the characteristics of the particular batch of reagent strips can be printed on the reagent strips or on a box of reagent strips and manually entered into the analyzing device to provide for such compensation. One such system is disclosed in U.S. Pat. No. 4,852,025. In other systems, the batch specific information can be coded on the reagent strip itself and read by the analyzing device to eliminate the need for a manual entry of data. Such data can be encoded on the reagent strip in the form of a bar code as disclosed in U.S. Pat. Nos. 4,476,149; 4,510,383; and 4,592,893 or in a magnetic format, such as disclosed in U.S. Pat. No. 4,578,716.
While such systems do provide a way to compensate for variations between batches in the parameters of reagent strips, the manual entry methods require the attention of an operator and are subject to input error, while the optical and magnetic systems require sophisticated reading equipment.